Construction – Geronimo/370

Common mode filters

Posted on2022-05-212022-05-212 Comments

This afternoon, I will be taking my Novice exam. So in preparation of being allowed to transmit, I decided to create a barrier for HF. I did so by making a number of loops (7) in the coax cables, just above the ceiling. These loops act as coils and they… Read the rest

Fixing old Nixie Clock (3)

Posted on2022-04-282022-04-28

Capacitor replaced The replacement of the power supply capacitor with a new one cleaned up the pulses nicely. The clock is running properly again for about two days now.… Read the rest

Fixing old Nixie Clock

Posted on2022-04-102022-04-13

Father’s clock My father built a Nixie clock in ‘ye olden days‘, over forty years ago… It was a relatively simple design compared to what we build nowadays. Design and simplified workings The clock derives it’s clock-pulses from the mains power, 50 Hz here in the NetherlandsDividing it by 50… Read the rest

Retro Z80 computer (9) – BLINKENLIGHTS

Posted on2022-01-212022-01-21

A small project today. I added ‘BLINKENLIGHTS’ to my Z80. This term stems from an old sign that used to hang in computer rooms: ACHTUNG!ALLES TURISTEN UND NONTEKNISCHEN LOOKENSPEEPERS!DAS KOMPUTERMASCHINE IST NICHT FÜR DER GEFINGERPOKEN UND MITTENGRABEN! ODERWISE IST EASY TO SCHNAPPEN DER SPRINGENWERK, BLOWENFUSEN UND POPPENCORKEN MIT SPITZENSPARKEN.IST NICHT… Read the rest

Retro Z80 computer (7) – Almost complete

Posted on2021-12-212021-12-22

Here’s a picture of the progress so far. It now also includes a RTC (Real Time Clock) module. What you might also notice is the flat cable I attached between the serial card and the serial to USB connector. That connector, as you can see in previous posts, was attached… Read the rest

Retro Z80 computer (6) – It works!

Posted on2021-12-16

I am one happy maker, I got my Z80 computer working right after building. All went well! The first lines of output are the boot screen: CP/M And of course I wanted to see CP/M running: Z80 Basic And after that, on to Z80 Basic version4.7b:… Read the rest

Retro Z80 computer (5) – Dual Clock Module

Posted on2021-12-162021-12-16

Without an internal clock nothing happens inside a computer. It’s the clock that makes the computer ‘tick’, chew away instructions that is. Last I assembled this module; it contains two clocks. Both clock signals are being put on the bus on the Backplane board. It’s starting to look like something…… Read the rest

Retro Z80 computer (4) – Dual Serial Module

Posted on2021-12-15

And another one bites the dust… The Dual Serial SIO/2 module has been assembled and soldered. With this one I had to search for the value of the resistors, because the info was not in the documentation. Eventually I ended up looking at the pictures of an assembled one online… Read the rest

Retro Z80 computer (3) – Memory module

Posted on2021-12-152021-12-15

And the memory module for my Z80 computer is finished. It contains 512K of ROM and 512K of RAM memory.… Read the rest

Retro Z80 computer (2) – backplane and CPU board

Posted on2021-12-152021-12-15

Yesterday evening I assembled and soldered the backplane board and the CPU board. Around 600 solder joints…… Read the rest

Retro Z80 computer (1) – plans

Posted on2021-12-112021-12-15

This holiday season I’m going retro, and build my own Z80 computer from a kit. The kit offers all the separate parts and one has to assemble the whole thing… All the parts Modular design The design of this computer is totally modular. Because it has been thought out very… Read the rest

HAM-gadget (6) – adjustment & enclosure

Posted on2021-11-132021-11-13

In this version I built in the possibility to adjust the summer and wintertime offset from UTC. It’s a very crude offset, I just add or subtract the offset from the UTC hour. Have to think of a better way to do this… Enclosure I built in the gadget in… Read the rest

HAM-gadget (5) – menu structure

Posted on2021-11-072021-11-08

This weekend I built in a menu structure into the HAM-gadget. Also I created a possibility to store and retrieve settings to the ATMEGA328P’s EEPROM, so they are saved for the next time you switch on the device. For now, you have to retrieve them manually, but that’s quicker then… Read the rest

HAM-gadget (3) – connected the GPS

Posted on2021-10-242021-10-24

Finally got it to work After much fiddling and trying out different libraries I finally had a bright moment and reverted back to the library that has been specifically made for this GPS module by Velleman… Duh… prototype, software version 0.5 That worked, also after some tweaking of the wires… Read the rest

HAM-gadget (2) – new Arduino board

Posted on2021-10-232021-10-23

Arduino board left and center, GPS module on the right, GPS antenna on top Today some new stuff arrived. First of all the new Arduino RP2040 Connect board, a Wifi capable board with a much smaller form factor then the Uno clone I had before. Second came in the GPS… Read the rest